监控c3p0的连接池

            SqlSession session = SessionFactory.getSqlSession(dbid);
            List<Map<String, Object>> resultList = session.getMapper(Mapper.class).getData(params);
            ConcurrentHashMap<String, SqlSessionFactory> sessionFactoryPool = SessionFactory.getSessionFactoryPool();

            Enumeration<String> keys = sessionFactoryPool.keys();
            while (keys.hasMoreElements())
            {
                String dbid = (String) keys.nextElement();
//                System.out.println("dbid : " + dbid);
                SqlSessionFactory sqlSessionFactory = sessionFactoryPool.get(dbid);
                Configuration configuration = sqlSessionFactory.getConfiguration();
                Environment environment = configuration.getEnvironment();
                DataSource dataSource = environment.getDataSource();
                if (dataSource instanceof PooledDataSource)
                {
                    PooledDataSource pds = (PooledDataSource) dataSource;
                    Collection allUsers = pds.getAllUsers();
                    System.out.println(allUsers);
　　　　　　　　　　　　//获取总连接数
                    System.err.println(dbid + ": num_connections: " + pds.getNumConnectionsDefaultUser());
　　　　　　　　　　　　//获取使用中的连接数
                    System.err.println(dbid + ": num_busy_connections: " + pds.getNumBusyConnectionsDefaultUser());
　　　　　　　　　　　　//获取空闲连接数
                    System.err.println(dbid + ": num_idle_connections: " + pds.getNumIdleConnectionsDefaultUser());
　　　　　　　　　　　　//获取未关闭的连接数
                    System.err.println(dbid + ": num_unclosed_connections: " + pds.getNumUnclosedOrphanedConnectionsDefaultUser());
                    System.err.println();
                }
                else
                {
                    System.err.println("Not a c3p0 PooledDataSource!");
                }
            }
            return resultList;
        

控制台输出结果

dbid1: num_connections: 10
dbid1: num_busy_connections: 0
dbid1: num_idle_connections: 10
dbid1: num_unclosed_connections: 0

dbid2: num_connections: 10
dbid2: num_busy_connections: 7
dbid2: num_idle_connections: 3
dbid2: num_unclosed_connections: 0

dbid3: num_connections: 10
dbid3: num_busy_connections: 0
dbid3: num_idle_connections: 10
dbid3: num_unclosed_connections: 0